My understanding is that what is being done is addressing issues related with people who have been determined to be a danger to themselves or society by a licensed psychologist or psychiatrist. People who have been committed by the courts to a hospital. We already have these checks in place in California and I am not aware of any mentally ill mass shooters here since Patrick Purdy. However these checks are NOT in place in some other states... Particularly in some where mass shootings have occurred. It is important to note though that in some mass shootings (comlubine, newton) weapons were obtained through irresponsible family members... So nothing is really a complete solution in itself.